LIVERMORE, California (AP) -- The national debate over protecting fragile species comes to life here, where upscale housing developments push ever deeper into the rumpled blanket of grassy hills at the eastern edge of the San Francisco Bay area

The threatened California red-legged frog breeds in the weedy creeks hidden in the hollows of this landscape, part of more than 4 million acres that the U.S. Fish and Wildlife Service proposed in 2001 to designate as essential for the frog's recovery.

In mid-April, following years of litigation and debate, the agency announced the designation of just 450,000 acres of critical habitat -- 11 percent of the original proposal.

It did not include a pastoral section of Livermore proposed for a 650-home development, or any part of the county commemorated in Mark Twain's short story "The Celebrated Jumping Frog of Calaveras County," which introduced the red-legged frog to the world.

Federal officials said the final decision was based on research that allowed them to zoom in on frog-friendly areas, sparing private landowners hundreds of millions of dollars in lost development opportunities. But environmentalists are protesting what they see one more example of the nation's weakening will to protect endangered wildlife.

"This decision is political, it's not scientific," said Carlos Davidson, director of the Environmental Studies Program at San Francisco State University.

The largest frog species in the West was once common across much of California, but it's now found on just 30 percent of its former habitat, Davidson said. It was listed as threatened under the Endangered Species Act in 1996.

The federal law has been the target of recent attacks, from lawsuits filed by developers to a bill introduced by House Resources Committee Chairman Richard Pombo, R-California, which would stop critical habitat designations in areas where it would stifle development.

"Property owners are a big part of the recovery equation and should not be victims of arbitrary and overzealous regulations," said Brian Kennedy, spokesman for the House Resources Committee.

Of the 1,300 species listed as endangered or threatened since the law's enactment in 1973, only 17 have recovered -- a sign of ineffectiveness, critics like Pombo say.

Proponents say just nine of the 1,300 listed plants and animals have gone extinct, and they call that a measure of the law's success.

With its recent and contentious habitat designation, the red-legged frog has jumped into the middle of the debate.

"For better or worse, the frog has become a symbol of what's wrong with the act if you're on one side, and what's right if you're on the other," said Robert Stack, a biochemist with the Jumping Frog Research Institute, which works to ensure the survival of amphibians native to the Sierra Nevada.

As part of the endangered species designation, land is identified as critical habitat, limiting opportunities for development. That, in turn, could limit the availability of affordable housing in the state, said Paul Campos, general counsel for the Home Builders Association of Northern California.

"The environmentalists pushing this would like to see the entire state designated for one species or another," he said. "But you have to put this into a larger context. We need to provide housing for our future citizens."

His group sued the Fish and Wildlife Service over its initial proposal to set aside 4.1 million acres of red-legged frog habitat. The resulting court order required the agency to account for the cost of lost development opportunities and led to substantial cuts in acreage.

Federal officials defend the reduction, saying it's better to work with private landowners, who control most of the land where the frog, Rana aurora draytonii, is found, than to burden them with regulations.

For example, Fish and Wildlife is exempting ranchers from fines if they kill frogs during routine ranch work. Because both cows and frogs need open space and watering holes, work done to maintain ranches shouldn't be penalized, officials said.

In the past, ranchers had no incentive to help the frog survive on their land, said Al Donner, a Sacramento-based spokesman for the Fish and Wildlife Service.

"The old attitude was shoot, shovel and shut up," he said. "Now we hope landowners will come forward and work with us."

But conservation groups accuse the Bush administration of pandering to private interests at the expense of endangered and threatened species.

Of the 312 critical habitat proposals considered since Bush took office, 94 percent were cut, according to the environmental organization Center for Biological Diversity. The reductions averaged 79 percent from what was originally proposed, the group said. In contrast, 35 percent were reduced by the Clinton administration, and by an average of just 5 percent, it said.

"This administration is hostile to the idea of critical habitat," Davidson said.

In Livermore, the benefits of pastures over pavement are clear.

On the nearly 1,000-acre ranch that's been in Tim Koopman's family since 1918, tiger salamanders, red-legged frogs and other threatened species find refuge from the golf course, housing development and freeway that surround it.

Fencing and solar water pumps, paid for partly with government funding, allow cows and frogs to reach water without getting in each other's way.

Ranching is a low-return business, Koopman said. If helping to protect endangered species keeps his land out of the hands of developers, he's all for it.

"We're here for the long haul. We want to take care of the land, and take pride in providing habitat," said Koopman. "It just doesn't have to come as a burden."

But environmentalists don't want the future of the red-legged frog to depend on the goodwill of landowners, ranchers or developers.

"If it's voluntary, there are no teeth, no limits," said Kieran Suckling, policy director for the Center for Biological Diversity in Tucson, Arizona. "If someone wants to protect habitat, we're all for that. But why choose one or the other?"

Copyright 2006 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.